Wednesday, July 17, 2013

The Malthusian Tipping Point

Following along on my previous post ... .

Assuming that McCloskey has correctly described the historical evidence, per capita real income was roughly stable at a low level most of the time, over most of the world, for thousands of years. That ceased to be true starting about 1800 when, first in Northwestern Europe and then over a wider and wider area, real income began to rise. The global average is now, by a conservative measure, about ten times what it was through most of history, and about thirty times as high if we limit ourselves to the developed world.

This pattern raises two puzzles:

1. What mechanism kept it stable for so long?

2. What changed?

The obvious answer to the first is something along the lines suggested by Malthus. Increases in income caused increases in population, increases in population pushed income back down. The equilibrium income was thus at a level that produced a roughly constant population.

What could have made that mechanism stop working? In my previous post, I suggested that economic and technological developments made land a less important input to production than it had been in the past, hence made income less sensitive to population. One should add to the model positive effects of population density. A denser population increases the opportunities for specialization and economies of scale. It increases the number of people creating productive innovation, intellectual property broadly defined. Looking at the modern world, it is hard to see much evidence that population density has, on net, a net negative effect. A few sparsely populated countries get substantial income from their natural resources, but most rich countries are densely populated and the obvious exception, the U.S., does not derive a very large fraction of its income from agriculture, the most obviously land-intensive industry.

That suggests one simple answer to the puzzle. Changes were occurring which lowered the importance of land in production. As long as income remained sufficiently sensitive to population density for the Malthusian mechanism to work, the change slowed the speed with which higher incomes were eliminated by the resulting population growth but did not change the equilibrium level of income. When the negative effects of population growth became small enough to be at least balanced by the positive effects, the system hit a tipping point, since there was now no equilibrating mechanism holding incomes down.

This answer assumes that the feedback mechanism went through pressure of population on land, as per Malthus. Are there other interesting alternatives?

One is predation. Primitive societies have small governments because they cannot afford large ones—if a significant part of the population is in the business of living off others instead of producing, everyone starves. Perhaps what maintained the equilibrium was that, as soon as incomes got large enough to support a predatory state, such a state came into existence. To put it in less abrupt terms, whenever increased incomes allowed the state to grow, it grew. Its consumption then pushed average incomes back down.

That story appeals to my libertarian prejudices, but, unlike my first suggestion, it does not offer an obvious explanation of what eventually turned off the mechanism. Perhaps the answer is some variant of McCloskey's. Beliefs changed, rhetoric changed, social norms changed, in a way that made predation a less viable strategy than it had been before.

When I have finished reading her book I may have a clearer idea of how that might have happened. Until then, it is worth looking for other candidates, other mechanisms that could have held real incomes at an equilibrium level for a very long time, then stopped working. Any solution must explain not only my two points above, but also a third: The fact that, whatever the cause, it was contagious. Technology could explain that, as one society imitated another. So, perhaps, could ideology—economic success makes good advertising.

The effect of contagious diseases might depend on part on population density. Could one tell a version of the story based on that? On other mechanisms? Suggestions welcome.

The serious one: Agglomeration Effects and Network Goods. Population density gets to a point at which agglomeration effects kick in and all sorts of new network goods become viable. Does that make any sense at all? I thought it sounded good but now I write it down I'm less sure!

The less serious one: related to the contagious disease idea in a way (though not the way you're using it) - TEA! As in the drink.

There is this apparently statistically evidenced idea that population density in the UK, the cradle of the industrial revolution, was able to get to some kind of tipping point for hyper-growth because people drank tea in Britain. Tea is a natural antiseptic it turns out, so populations that drank tea could live in higher densities with less propensity to catch common but debilitating illnesses like colds and flu.

In the other great tea drinking cultures of the east, technology was not in a position to let them exploit this benefit. In Japan, for instance, they had virtually "unlearned" the wheel and more labour was devoted to manual fetching and carrying.

Oh, and maybe another one, a sort of Georgist one. This one's a bit thinking out loud here, so go with me a little way…

There's both a supply and a demand effect in this (I think).

On the labour supply side, working back from the Georgist maxim that "when land is free labour is dear". Agricultural (and storage, transport etc) technology shifts the mnargin of production out and rents up (and assisted by government intervention like enclosures) created a semi-indegent and fairly plentiful supply of labour at (now falling because of the agri-technology leap) subsistence levels.

On the demand side, industrial technology concentrations were able to reach a sort of critical mass where their demand for labour was sufficient to pay the rapidly rising rent in growing urban areas.

Or is that completely whacko? Is it more or less the Lewis Growth Model, just expressed from a Georgist perspective?

You think, Tibor? Maybe. I'll have to ponder it. My off the cuff rejoinder would be "well how does that explain the relatively less growth in countries where tea was a staple not a luxury?" The tea and the technology had to be there at the same time so to speak for the urbanisation to be successful.

But that needn't actually make either of us wrong, maybe: that tea was the medicine becoming popular at just the right time such that (again together with leaps in maritime & shipping technology/capital increasing supply) there developed some herd immunity that enabled increasing urbanisation. Tea was a catalyst sort of thing! :) Well, tea and Jenner!

Are you aware of Douglass North's theory of credible commitment? It's interesting because it has not merely a link between economic productivity and legal security of property and contracts, but a mechanism by which this combination gives rise to enhanced military success.

@Stoddard: North's theory would form half of a useful feedback loop, but for a free (or freer than now) country to be sustainable, we need to come up with a way to provide the other half: make military success lead to the successful power being more, not less, likely to honor individuals' rights of property and contract.

The Icelanders David writes about certainly had part of the puzzle, and the folks in the underground economy may have another part. What's missing is a good regime of self-enforcing social mores, like Shasta County but much more comprehensive and with enough trust mechanisms and data gathering capability that it can make the reputation mechanism work, even to protect against government officials.

Such an effort (conspiracy?) needs organization and planning. For now I'm just tossing the idea out, to see if anyone else would find it worth exploring.

Perhaps things got better with the advent of better banking services including fiduciary media and clearing houses which really lowered costs to banks made lending easier and made business easier which of course led to good results all round.

I think the crux is indeed between the tipping point between positive and negative feedbacks of population density on itself.

'capital' of various forms plays a large role here; be it political or technological; or 'ideas' generally, to tie it in with this blog.

I think the question as to what the future evolution of this net feedback will be is an interesting one. It is one of those questions everyone at least implicitly seems to have very strong answers to, but I really wouldn't know.

Some days I can buy the singularity narrative. Other days I just don't see the things I am doing in my lab be anywhere near as transformative as the changes 200 years ago. We have transportation good enough for people and goods to be united in a global market. We can communicate at the speed of light.

What transformations of that magnitude will the future hold in order to ward off the good old negative feedback loop on population density? I don't believe anyone has a very compelling answer to that. Looking at empirical data, I lean more towards the notion that the most fundamental innovations where somewhat one-time events, and we are now in a phase where we are plateauing out into a 'great stagnation'.

Then again, people have said that before, and they have always been wrong in our lifetimes. Then once more, this type of extrapolation is essentially all that the 'bulls' rely upon.

Let's say we have country with three arable parts, one for 1 million farmers at productivity 2, one for 1 million at 1, and one for 2 million at 0.5. Productivity 1 means that you can sustain only yourself.

So the maximum Malthusian population would be 4 million farmers. But is that likely to happen? It would require someone using force to redistribute 50% of the food from the best area to the worst area. This could happen either by private theft or some kind of welfare program.

Another possibility would be something that happened in Sweden. The children at the good area would be plentiful and would divide their parents lot among themselves. Productivity fell after a few generations due to each family now having many small plots spread out around the area. We later had a reformation that solved this problem.

But let's say there were little theft (either private or state sponsored) and the productivity could be kept from falling (either by government action or by cultural norms). I suspect that the stable situation would be 2 million farmers sustaining 3 million people. This could allow for an industrial revolution with no threat from Malthus.

I don't see why this is so hard. There are many societies still here, today, who are still in or near the Malthusian trap. We don't have to guess about ancient history. The answer is clear - the return to savings for individuals in those societies is highly negative.The state might be partly to blame because dysfunctional states don't protect the property rights of the poor well. But, parallel with McCloskey's thesis, there is very little means for individual savings, because culturally they have not accepted bourgeois rhetoric. Frequently members escape by moving to the west, where they can split the difference by sending back remittances, but the distance allows them to keep some for their own individual savings.

About the hockey stick, I can easily imagine the upward turning blade. We have enjoyed great progress since the industrial revolution. But I doubt the long and level handle of the hockey stick, the idea that “…per capita real income was roughly stable at a low level most of the time, over most of the world, for thousands of years.” I would appreciate it, David, if you could tell one or two of Dierdre McCloskey’s sources for her echoing this idea. I hope her source is not Robert Lucas’s book Lectures on Economic Growth, about which I commented before.

Such an idea is a common error in human thought, I believe. The basic error is to assume that everything far away from my present views of life, remote from my present concerns, must be all about the same. I guess the error occurs because I can safely lump all those remote things together under one term. Indeed, I should stereotype in this way. It would be a mistake for me to develop the instruments with which I could discern differences among those remote things because of my opportunity costs in this life here today. Examples of such one-term over simplifications are: intelligence, protoplasm, and per-capita-income-more-than-200-years-ago. Each such term serves a purpose in a time and place.

I never believed Malthus’s famous theory. It suggests that life is stupid. It suggests that a population would survive through time with the members perpetually weakened, at the edge starvation. It suggests that life could not find ways, other than starvation, to limit the size of populations. But there is plenty of evidence that populations have ways of limiting their numbers, as I commented before, ref. Richard Dawkins.

About your theory of predation, David, I agree, and have published a theory. In the greatest empires in human history, first property rights grew, then the state grew, then the whole corrupted and died.

Jock: Well, for most the most part the technology of the west (lands where tea was a luxury) was not better than that of the east (as a matter of fact, it had been worse worse ever since the fall of the western Rome until the renaissance) and if the "tipping points" before roughly 1800s were not achieved in Europe only because every time there was a chance for it, the crucial ingredient - tea - was missing, that is if tea was actually that important you would see dramatic developement in India, Japan, Indonesia and other tea-filled countries before it happened in Europe.

And basically, if your explanation is "technology+tea", you can drop the tea and the explanation will still hold the same value I think. Before the industrial revolution there has never been such an advanced technology anywhere...tea really doesn't come as any more necessary than silk for example. You could say the same things about silk (although more people could surely afford silk than tea).

And although tea can be healthy, the problem is exactly the same as with vaccination - it works in the other direction (if probably only really slightly) - increases the amount of people while not improving the technology at all.

I am thinking about the "predatory state". I am also skeptical about it, mainly because I too would like it to be true a little bit too much and it is perhaps just too convenient...

And also if it worked that way, it would not explain the relatively non-intrusive states of the 1800s. The society started to gain wealth first I think (beginning of the industrial revolution) and only then came the reduction of the state. At the same time the absolutist monarchies were not established after a period of wealth increase...of course the fact that something happens even without A (previous wealth increase) doesn't mean it usually doesn't happen that way. But I think it is perhaps even more common for a absolutist state (or totalitarian which is essentially the modern version of the same thing) to establish after a period of disarray. Roman Empire came into existence after an era of internal conflicts, the nazi and communist regimes in Europe both were capitalizing on previous unstability, the shogunate in Japan, which was arguably more strict and more caste oriented than the previous empire also emerged from an era of struggles. I don't know how it was with the european absolutist monarchies,what was the reason of the shift from the feudal to absolutist states. And the only examples of a shift of a rich more free society towards a more intrusive states that I can think of are the beginning of the 20th century and subsequently the 1960s onward with a slight exception of the 1980s and early 1990s (drop the word slight in the now former communist countries).

I think the right answer may simply be the simplest one - technology. It reduced the importance of land from a situation in which 95% or so of population barely managed to feed the society to one where 5% make abundance of food and there are there is no more famine anywhere for other than political reasons (it is of course hard to make a living in a country where there is a pretty much constant civil war or where a dictator decides to make a "giant leap forward"). Of course his suggests boosts in population as well, but apparently the tipping point happened when a technology was discovered that had so vast benefits other than those that help the population that the "pendulum" shifted more than usually from the stable point and reached the other stable point which we seem to be living ever since (and the pendulum seems to be good although too "strict" a metaphor - the current stable point is the upper one at the pendulum which is more shaky...of course the metaphor breaks a bit as it cannot really be as shaky as the upper pendulum stable point which would almost surely never - in the mathematical sense of almost surely - happen as long as it is not the starting point of the system).

From memory, Deirdre uses Angus Maddison's data. Note that not only is per capita GDP stable, it is also close to subsistence levels. This is confirmed in archeological studies.

This trend seems weird, but can be explained by the effects of negative feedback. In a land based society Malthusian effects are cruel. Prosperous people can raise more babies, thus their population tends to grow up to the point where average productivity per person reverts back to subsistence level (well, above subsistence in good years and below in bad).

The way to think about it is that economic progress must occur faster than the Malthusian limits of population growth, not short term, but permanently. Otherwise it is back to near subsistence.

Sure a society could control fertility due to institutional constraints such as delayed marriage. But this assumes a single society. That delayed fertility society would subject to internal and external forces that undermine it. A subsegment that doesn't control fertility will quickly dominate, and any neighboring society which is facing starvation is strongly rewarded by using their growing numbers to steal everything the wealthy society has.

I wouldn't say life is stupid,just that evolution is cruel, and I have read just about everything Dawkins has written.

I agree that there are two streams or forces that one must consider to understand the great human breakthrough of modernity.

The first involves headwinds. I would summarize these in four categories. Malthusian, exploitation, incumbency and culture. Each involves strong negative feedback.

The Malthusian curse requires that technological progress not just be constant over centuries, but that it be faster than population growth's drag on resources. As you mention, in land based societies, they are kind of paddling against a torrent.

I agree with your comment on exploitation, and will only add that it can come from three directions, each of which grows as prosperity grows. It can be from within, without or above. Any society able to outsmart the Malthusian curse due to technology, institutions or whatever becomes a juicy target for internal parasites, external predators (neighboring states or barbarians) and most importantly, from above. Most larger and wealthier states get exploited by stationary bandits which milk the rest of the population. Thus ninety percent of the population exists at subsistence, while the upper class lives better. (Peter Turchin even extends the models to the wealthy exploitative class, which goes through booms and busts).

The next category is distinct but similar to exploitation. It involves the fact that progress requires change, and that change creates winners and losers. Incumbents rationally resist change. There is almost always a power imbalance between incumbents and potential entrants, and the incumbents use this to stop any change which threatens them. Luddites, protectionists, priests, rent seekers, etc.

The next factor, which I believe "Dignity" is a subsegment of, is culture. Some cultures resist change and others promote it. Neither is inherently superior,but some combinations lead to growing prosperity and most don't.

On the other side of the ledger, are the forces which promote growing prosperity and well being. To understand these, we need a framework for progress. Mine is pretty simple: progress can be modeled as solving more problems than are created. The algorithm of progress is:1) solve problems (via variation and selection), 2) spread the solutions over time, space and numbers (preserve them, share them, replicate them), and3) build upon them (combine, ratchet and or make the positives more outweigh the negatives)

Progress comes about by an algorithm of problem solving, spreading and building. We learn, and better yet, learn to learn better.

The modern breakthrough came about when some northern European states were able to solve problems at a faster rate than the headwinds that worked against them for a period of centuries. We were able to progress at a rate which started small, but by the 19th C grew to about two percent per year.

One possible explanation for the sudden takeoff would be the invention of science as an institution, and specifically the pioneering role of the Royal Society. I'm not referring to science in an abstract epistemic sense, but to social features of science, such as open publication of knowledge, credit for discovery going to first publication, requirements for replication of findings, and the like. Remember that the Royal Society wasn't just about abstract theory; one of the early bodies of research submitted to it was John Graunt's studies on causes and rates of death, which gave rise to the modern life insurance industry (and after just a few years). China, for all its advanced technology, never developed this kind of public pooling of knowledge.

This is a longer answer and is not simple, but it relates to the above algorithm.

First, they had what J. Diamond refers to as a level of intermediate fragmentation, and which I call constructive competition. You had lots of independent competing states with differing cultures and institutions which due to the advent of printing and the Republic of Letters and the continuing advancement of transportation (especially shipping), were highly interconnected. We had lots of people and institutions, with no central ability to exploit them. Those seeking freedom or freer enterprise could and did go to the next city or state.

We basically see a type of social evolution. First the Italian states flourished. As the incumbents and predators take over, the entrepreneurial forces move to Belgium, then Amsterdam, then across the channel, and then across the Ocean. Someone, somewhere has been able to grow at a faster rate than the headwinds. Since knowledge is easier to spread than create, those not at the vanguard could draft off those that were, while no single prince or parasite could exploit the situation as their subjects (or their ideas) always had some degree of exit rights.

I could go on longer, but just want to add one other huge Gorilla in the room which was unique at that time. For five hundred years, the Europeans had a rare opportunity of open acreage. Three continents substantially larger in size and agricultural diversity than their homeland. This reduces Malthuian pressures somewhat and created an opportunity for more exit rights or escape privileges. For five hundred years, those feeling repressed had the ability to go west. And they did, setting up new states with slightly more free from exploitation and incumbents. At least for a while...

Not every culture had the right combination for economic progress. However, for centuries no state outside of Europe was able to prey upon the progressing states of Europe, and at no time was any single state within Europe able to gain control of the whole.

"I suggested that economic and technological developments made land a less important input to production than it had been in the past, hence made income less sensitive to population."

I don;t quite get this argument. Sure agric fell as a percentage of GDP with the advancement of industrialization. However food is still unavoidable and the Malthusian theory should still have applied. I can't eat accounting services for instance.

Could colonialism have had an impact? At the same time the Northern European countries began rapidly developing their economies, they were also exporting a large portion of their population to their various colonies, and then to the new nation of the USA. This even occurred with countries without large colonial empires, such as Norway and Sweden.This may've kept the rapid increase in population density that occurred in Europe at the time down to a tolerable level. Without the safety valve of emigration, maybe Malthusian pressures would've pushed the European economy back down to traditional levels.

Although old-style colonialism is mostly a thing of the past now, you'll notice that high rates of emigration from industrializing countries has continued.

It is impressive in a way. Maddison is clearly expert in estimates of historical population and GDP. And Maddison gathers data from many other sources. So I have learned of a large body of scholarship.

But I see almost no support for an assertion such as “per capita real income was roughly stable at a low level most of the time, over most of the world, for thousands of years.” Here are three reasons: 1. There are differences in per capita GDP from region to region. 2. The text reports many estimates of declining wealth in aging regimes, e.g. in Italy from 1570-1700. A decline must have started higher and gone lower. This is not constant. 3. Many of the specific looking numbers clearly were generated from gross assumptions and not from historical evidence. For example, look at Eastern Europe and Former USSR for the years 0 and 1000. In tables B-10 and B-18 we see estimates with three significant digits. But in table B-21 we see a rounded and candid guess: $400 per capita GDP, one significant digit. Arithmetic shows the three significant digits in table B-18 derived from the three significant digits in table B-10 (obtained from somewhere) multiplied by the one-significant-digit guess in table B-21.

It is still safe, of course, to conclude that people before 1800 had much less than we have today, and they had almost zero of the manufactures we enjoy today. But just because you are getting near to zero does not mean that the ratios of those numbers near zero approach one.

I continue to believe that my ancestors were successful in improving their living conditions, even before the industrial revolution.

I agree they were able to improve their situation and make technological and institutional improvements. It is just that the long term result was greater population, due either to growth rates or immigrants attracted by the wealth. Thus the trends show per capita long term growth rates approaching zero. Any other positive number over centuries would lead to widespread prosperity of a kind not known to exist anywhere. ( and a negative number would be extinction)

When you add in that the elites can and did exploit the masses, you also get a situation where any surplus went to a minority. Lots of people at subsistence or just above and a few living substantially higher.

The interesting thing about exploitation is that seen from the long range, the net effect of more exploitation is just fewer people at the same Malthusian level of subsistence. Not trying to defend it or anything, just saying it is interesting....

I continue to argue against an idea that “…per capita real income was roughly stable at a low level most of the time, over most of the world, for thousands of years.”

For one thing this overlooks all the ups and downs of empires. In Conquests and Cultures Thomas Sowell reports that Britain had a higher standard of living—during the time it was occupied by Rome—than it had either before that time or after that time for the next thousand years.

After the Romans withdrew, in the early fifth century A.D.:

"The use of coins declined. Pottery ceased to be mass produced. Roads and waterways fell into disrepair. Central heating and hot baths disappeared for many centuries. So did bricks, which the Romans used, but which did not reappear in Britain until the fourteenth century, when they were imported from the continent. Glass bottles, which had been produced in Roman times, disappeared from England and did not reappear until Elizabethan times, when bottles began to be imported from Venice, and it was the seventeenth century before glass-blowing was re-established in the British Isles." (page 27)

This is not a story of roughly stable per capita income. Rather it is the story of a fall and then again a rise. Significant changes of historical per capita GDP may become visible, I believe, to one who looks at history with appropriate instruments.

Also note that the Roman-times standard of living was regained centuries before the onset of the industrial revolution. This seems to be another failing of the hockey-stick notion, with its change of slope occurring at the start of the industrial revolution around 1750 or 1800.

Richard: Thanks, that is a nice rebuttal. I wonder what McCloskey has to say about that. Both of you can't be right after all :) Now, I find your view to be more convincing, then again I have not read McCloskey's book.

Perhaps I am learning that reports of evidence carry more weight than my reasoning. So here is another report of evidence. From Angus Maddison’s appendix, page 247:

Jan de Vries (1993) is very critical of the real wage approach compared with alternative quantitative methods of measuring well–being. He questions the representativity of construction worker experience in a society with wide income differences. He emphasises the large number of important items left out of the Phelps Brown index and its use of fixed weights for such a long period, but his strongest doubts arise from the conflict between its sombre conclusions with evidence of a different kind which he found in probate inventories “All the studies I have examined for colonial New England and the Chesapeake, England and the Netherlands consistently reveal two features. With very few exceptions, each generation of decedents from the mid–seventeenth to the late eighteenth century left behind more and better possessions.”

Richard: Well, the mid 17th to late 19th century is during the industrial revolution already. Still, those previous examples are worth examining, because they seem to disprove the hockey stick argument.

The anecdotal evidence is almost impossible to square with the 'statistics'. We know that England in Shakespeare's time wasn't a subsistence society. Ordinary people went to plays, frequented taverns , engaged in commerce; (from Henry VIII, Act I, Scene 2);

--------quote-------Not almost appears,It doth appear; for, upon these taxations,The clothiers all, not able to maintainThe many to them longing, have put offThe spinsters, carders, fullers, weavers, who,Unfit for other life, compell'd by hungerAnd lack of other means, in desperate mannerDaring the event to the teeth, are all in uproar,And danger serves among then!-------endquote-------

Shakespeare stole all that from Holinshed, but it indicates a developed economy, with a division of labor, and dead weight loss of taxation.

Here's a good description of just how developed England's theaters were by the late 16th/early 17th century;

http://www.2blowhards.com/archives/000222.html

--------quote---------The London theaters represented a revolution in culture; they were apparently the first capitalist businesses in the world built entirely around entertainment. The heart of this cultural business model was the actors company, in which a group of actors invested money in a common stock of properties, costumes and plays. Each company of actors obtained finance from an impresario, who got a share (usually 50%) of the box office. Shakespeare was 10% owner not only of the Chamberlain's Men but also of the Globe (that is, the building and real estate itself.)

Theaters were big business for the time. Costs included hundreds of very expensive costumes (velvet cost 1 pound a yard), plays (which if bought freelance were usually purchased outright for about 6 or 7 pounds), the salaries of "extras" and minor actors on stage and the salaries of about 30 paid hands (including musicians, actors, prompters, bookkeepers, stage keepers, and wardrobe keepers) behind the scenes. Hundreds of playbills, pasted up around the City, served as advertisements. The range of business affairs was so complex that each company had an administrator, usually called an actor-manager.------endquote------

Egypt had surplus food for a long, long time--centuries, for sure, maybe millennia--due to the deposits brought by Nile flooding. They had so much surplus food that other empires considered the place worthy of fighting over, just to gain control of all that surplus grain.

So why didn't Egypt fall into a Malthusian Trap? Why didn't the population expand until there was no surplus, or over-expand, causing a massive die-off. Aside from the Plague of Justinian, were there any catastrophic reductions in population? Why didn't the incredible surplus of food allow Egypt to dominate its neighbors, instead of being dominated? Egypt was, at times, relatively wealthy, compared to other places and times, but it never approached anything like an Industrial Revolution.

There's got to be something more to this than escaping the Malthusian Trap.

If we note that what places the Malthusian cap on population is not the average harvest, but the worst-in-a-generation harvest, then most societies most of the time can live well above minimal subsistance.

This Malthusian quote might be a shocker to you guys...“I have said, that in the course of some centuries [England] might contain two or three times as many inhabitants as at present and yet every person be both better fed and better clothed.”